So I just read about this tip for when you need to give out your email address to receive some kind of free offer (sometimes you can get free software if you provide your email address). The problem is, then they send spam. So do this:
with gmail (may work with others, don't use them tho), is the use of periods. if your normal email address is email@example.com, then use firstname.lastname@example.org when signing up for things that may start spamming you. Then set up a filter in your gmail to send anything that is addressed to email@example.com into a junk folder, or simply delete so you'd never see it. That's what I've done and has made life very pleasant.
Gmail ignores periods, so the mail will still come. But you can set up a filter to remove any mail using periods.